1. Field of the invention
The present invention relates to an expansion valve, more particularly an expansion valve, which can be used in air-conditioners and refrigerating systems, and which has a filtering mechanism, dryers, and an expansion mechanism integrated therein.
2. Brief Description of the Prior Art
Conventionally, foods such as meats and vegetables are made dry with sunlight or pickled so that they can be preserved for extended period of time. With the advent of refrigerating systems, it is possible to preserve foods for relatively long time without use of conventional means of drying with sunlight and pickling. And, transportation of foods to distant locations is made feasible, allowing consumers to enjoy much bigger variety of foods. And, air-conditioners also contribute a lot towards improvement of mankind""s life quality.
Either refrigerating machines or air-conditioning apparatuses have expansion valves fitted thereto for use in the refrigeration cycle thereof Referring to FIG. 4, a compressor 2, a high pressure pipe 21, a condenser 22, an expansion valve 23, an evaporator 24, and a low pressure pipe 25 are integrated in sequence to perform refrigerating cycles. In each refrigerating cycle, refrigerant is compressed by means of the compressor 2, and forced to travel into the condenser 22 via the high pressure pipe 21 to become pressured liquefied form, and then travels through the expansion valve 23 to go through the reduction and expansion process. After going through the expansion valve 23, the pressured liquefied refrigerant is transferred into the evaporator 24 to go through heat exchange process to provide cold for use. Finally, the refrigerant is forced to travel back into the compressor 2 via the low pressure pipe 25 by means of the compressor 2 for use in the next cycle. The expansion valve 23 is a very important part in the refrigeration cycle, and can be provided in various forms and dimensions according to needs. For example, capillaries can be substituted for expansion valves. In addition, a drying mechanism 26 can be arranged before the expansion valve 23 for absorbing water and impurities in refrigeration cycles.
However, the expansion valve 23 has disadvantages as followings:
1. Because additional filtering means and drying mechanisms have to be joined to the expansion valve 23, assembly of a refrigerating system will cost more labor and time. And, leakage of the whole refrigeration cycle is more likely to happen because additional joins are present due to additional filtering means and drying mechanisms.
2. When capillaries are used, it is relatively difficult to repair the capillaries because foamed fillers are usually used in the walls of air-conditioners and refrigerators as the lagging materials.
3. If filtration nets are arranged in front of capillaries, the capillaries are prone to get damaged or broken after long period of use due to vibration and friction of the filtration nets against the capillaries. And, conventional filtration nets can""t effectively filter off water, impurities, and greasy dirt that comes out from compressor oil of the compressor 2 used at high temperature for a long period of time. Consequently, the refrigerating system can be blocked with the above substances, causing the compressor to burn or breakdown.
It is a main object of the present invention to provide an expansion valve of refrigerating systems, which has a filtration means, drying mechanisms, and an expansion mechanism integrated therein, so that it can function more efficiently.
The expansion valve has a tube body, in which a first filtering net, drying agents, a bullet-shaped filtering net, and a reducing body are integrated. The first filtering net is disposed over the front end of the tube body. The drying agents are contained in a front portion of the tube body. The bullet-shaped filtering net is disposed in the drying agents along the front portion of the tube body. The reducing body is disposed in a rear portion of the tube body, and is joined to both the bullet-shaped filtering net and a rear outlet end of the tube body.